Overhead-doors are typically sealed by contacting a lower portion, typically the bottom edge portion of the door, and perhaps a seal, with the floor. However in many applications this can pose a problem where debris is located on the floor beneath the door because, when the door is closed against the floor, the bottom of the door and/or seal can come into contact with the debris. Also, debris in many forms including condensed moisture can contaminate the lower portion of the door by various means. Accordingly, when the door is opened, there is the potential for this debris to fall from the bottom portions or leading edge of the door and/or seal onto objects (e.g. food) and/or people passing through the doorway.
In order to prevent such debris from falling onto objects and/or people passing beneath the door, the Applicant of this invention has previously provided a protective body consisting of essentially a collection surface connected to a pneumatic cylinder. When the door is fully opened, the protective body substantially spans the width of the door and collects debris that falls while the door is fully open. When using this protective body however, as the door begins to close, the protective body is rotated from a position where the collection surface is substantially horizontal to the floor to a position that is substantially perpendicular to the floor. This leads to a situation where debris collected on the protective body will drop onto objects and/or people or the floor below when the guard is moved out of the path of the door. So while protection of contamination by debris dropping is provided during the fully open time of the door, during opening and closing, where traffic may still be in the door opening, contamination may occur. The present invention is directed towards structures and methods to solve these deficiencies and to provide new advantages in prevention of contaminating cargo or persons traversing the opening or passage while the door is still overhead.